This invention relates to a process for the separation of a butene mixture to produce an n-butene rich product and an isobutylene rich product in a fractionator wherein the reflux is isomerized before introduction into the fractionator. The resulting high purity streams and isobutene are useful in subsequent reactions to produce secondary butyl alcohol and methyl ethyl ketone from normal butylene and butyl rubber and lubricating oil additive from isobutylene.
The isomerization of olefins is generally well known in the petroleum refining art. The double bond present in olefinic hydrocarbons shift readily over various catalysts to a more central position in the organic molecule. Composites of a metal from Group VIII of the Periodic Table properly inhibited in their hydrogenation activity with a refractory inorganic oxide as well known catalysts in producing olefinic bond migration.